How To Bias an Amplifier ??? and Why ???

Discussion in 'The Squawk Box' started by BOBBO, Mar 11, 2008.

  1. lexluthier

    lexluthier V.I.P. Member V.I.P. Member

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    I've had a Hunt Dabney Bias Probe (the original one) for nearly 20 years and it still works great. Need a meter if you get one of those, though.

    Some of the new bias meters that also measure plate voltages are real nice if you don't want to poke around the tube sockets with a meter to find out the plate voltages.

    Lately I've just been using the WeberVST bias calculator instead of doing the math.
    Weber Bias Calculator
     
  2. coldsteal2

    coldsteal2 V.I.P. Member

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  3. Soldano16

    Soldano16 Senior Member

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    I think you may be wrong. That could cost a life.
     
  4. twinrider1

    twinrider1 Senior Member

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    I went with Amp-Head and was very happy with my experience. Great instructions and well built. Quick shipping and packed to survive a UPS lunch-break soccer match.
    I bought the "Dual Bias Tester-MPD" which shows voltage too.
     
  5. LPV

    LPV Senior Member

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    It is wrong, but its also besides the point. You adjust the bias with the amp turned ON. You can get killed if you are ignorant to the dangers, or you just plain f*ck up.

    As a side note, if you swap tubes and you amp sounds the same and the tubes aren't glowing like 100w bulbs, your bias is probably not too far off
    . Look for harsher tone (over bias) and really hot tubes (under bias) as an indicator of improper bias.

    Amp techs are our friends.
     

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